Flagnoting every print dimension - bad drafting practice? 3

[McLeod]

Some of our manufacturing and inspection staff are requesting that all prints in the company have every single attribute (dimension, note requirement, etc.) individually and sequentially labeled with flagnotes, so that they are more friendly to their inspection forms. Instinctively, the drafters, designers, and engineers in product development know that this is a Bad Thing, primarily because of the resulting clutter on the drawing and the inevitable revision nightmares. But are there any particular parts of ASME Y14 which directly or indirectly preclude such madness? I've been all over it and can't find anything which specifically addresses the rampant over-use of flagnotes or similar topic. Has anyone seen this put into practice? What were the engineers smoking when they agreed to it?

 

[MadMango]

I worked in the medical device field for a bit, and the inspectors would number each dimension for instection. They would do this by hand, writing a "1" and then drawing a circle around it, then "2" with a circle, etc... untill all dimensions and critical notes were marked. These numbers corresponded to their inspection form, where they would indicate how that particular feature was coming in (+/- .01mm).

I don't have a copy of ASME y14 onhand, but I know there is a passage in it that says that drawings should be "clean" and "easy to read". I forget the exact phrase. Adding flagnotes to every dimension and note would clutter the drawing. If you want my advice, fight this practice at all costs. "Happy the Hare at morning for she is ignorant to the Hunter's waking thoughts."

 

[ivymike]

In contrast to MM's approach, I'd offer token resistance to the idea, but cave to pressure when the boss finally comes around to see what the ruckus is all about. I'd walk away from the debate after saying something along the lines of "if you think this will work out, then I'm willing to try it, but I have serious misgivings." Then I'd wait patiently for the system to crumble under its own weight.

"When you're stuck between an immovable object and an irresistable force, try to find a comfortable crack to wedge yourself into until the issue is settled. "

or something like that.

 

[Hush]

My advice, resist, resist, resist. The last company I worked for tried this with horrid results. The numbering order changed with almost every revision, if QC doesn't record the revision number or worse goes by memory you end up with a real mess, usually popping up when you need the information in a hurry. The final compromise was to produce inspection drawings for product families numbering the critical dimensions on generic dwgs. I.E. if you have a group of fifty different valve sizes with six common critical features that must have the dimensions recorded, one generic drawing with these six features numbered will cover the lot. If your run sizes are small enough you can put the generic dwg right on the inspection sheet.

 

[MadMango]

Ivymike has the safer approach to your problem. = )

I found what I was looking for...

Global Engineering Documents DRM, 9th edition
ASME Y14.5M

Drawing Quality Control, Section 4.5.3.d
"Drawings should not include information pertaining to inspection or sampling, process, or production data such as tools, gages, fixtures or routing."

Fundamental Rules of Dimensioning, Section 5.5.m.
"Only the end product dimensions and data are shown on drawings unless essential to the definition of engineering requirements. When non-mandatory in-process manufacturing information is shown on the drawing, it shall be marked with a note similar to 'NON-MANDATORY, MANUFACTURING DATA'."

***

If you do have to identify every element of your drawings, give some thought into how you are going to mark these items. Triangle or Square note-flags are normally reserved for General Notes. Circular or Hexagonal note-flags are normally reserved forItem Numbers in assembly drawings. Parentheses (*) are normally used for Reference Information.

Brackets [*] normally depict Dual Dimensioning... but can also be used to identify In-house Peculiar Information. It sounds like that is what your manufacturing/inspection wants, "peculiar information" on your drawings.

You know how hard or easy it will be to make changes to these note-flags in the future, based on your drafting standards, practices and software your company uses. I'm just trying to give you some help in your fight. Good luck either way. "Happy the Hare at morning for she is ignorant to the Hunter's waking thoughts."

 

[McLeod]

MadMango - I've got a copy of Global Engineering Documents' ASME Y14 series - there's no edition listed, just the issue date of the individual ASME documents. I've been all over Y14.5M-1994 (the latest release), and can't find any reference to Drafting Quality Control. All of section 4 is about datum referencing. Was the first excerpt you listed from another document?

I did find the following section in Y14.5M:

1.4 Fundamental Rules
...
"(f) It is permissible to identify as nonmandatory certain processing dimensions that provide for finish allowance (etc...) Non mandatory processing dimensions shall be identified by an appropriate note, such as NON-MANDATORY (MFG DATA)."

This does not help much, though, as it pertains to the inclusion of in-process dimensions, rather than inspection flags.

I've also been all over Genium Publishing's drafting practices and standards manual, both hard copy and the online version (

http://www.dz.genium.com),

and have not been able to locate any relevant sections. The excerpt you quoted on Drafting Quality Control is excellent - I just need to be able to cite the correct source.

 

[MadMango]

McLeod,

In my copy of the Global Eng Doc DRM, Section 4.5.3 Drawing Quality Control is on page 4-4, bottom 1/3 of the page.

As for:

Fundamental Rules of Dimensioning, Section 5.5.m.
"Only the end product dimensions and data are shown on drawings unless essential to the definition of engineering requirements. When non-mandatory in-process manufacturing information is shown on the drawing, it shall be marked with a note similar to 'NON-MANDATORY, MANUFACTURING DATA'."

I would try to draw attention to the first sentance, "Only the end product dimensions and data are shown on drawings unless essential to the definition of engineering requirements." "Happy the Hare at morning for she is ignorant to the Hunter's waking thoughts."

 

[MadMango]

Oops, I forgot to add that in my copy of the DMR, Section 4 is Types of Engineering Drawings, and Section 5 is Dimensions & Tolerances. Maybe you need to look in your DMR for "Types of Engineering Drawings". "Happy the Hare at morning for she is ignorant to the Hunter's waking thoughts."

 

[McLeod]

MadMango - OK, so it's part of a Drafting Reference Manual (DRM?), not actually part of ASME Y14.5.

The Genium Publishing drafting manual has this to say in the "Drawings - Purpose and Classification" section:

2.2 Engineering Production (Manufacturing) Drawings

2.2.1 Engineering production drawings should provide complete engineering definition of the finished system, assembly, or part. This includes reference to supplementary data such as design data references, laboratory instructions, engineering instructions, etc., as appropriate. Manufacturing or processing instructions may also be provided for reference purposes only, unless such data are vital to end definition and engineering control of the product.

2.2.2 Engineering production drawings must not under any circumstances be prepared to accomodate a particular method of manufacture except as described above. In addition, such drawings must not include information relating to manufacturing work stations, as this kind of information should be part of the planning process.

2.2.3 Engineering production drawings should always be prepared so that regardless of location of manufacture, they can be used without additional explanation...

Hell, if drawings can't include manufacturing work station info, they certainly shouldn't include inspection info.

 

[Gianfranco]

Dear McLeod, MadMango, ivymike, Hush,

It seems that "Drawings - Purpose and Classification" manual is clear enough:
Let me excerp the last phrase because I like it a lot:

<<Engineering production drawings should always be prepared so that regardless of location of manufacture, they can be used without additional explanation...>>

It is nice and fruitful for all tech. people!! Why?
Let me do an observation first on your messages.

I read the words typical of a fight: resist, fight, rampant, madness, ...
Sometime, I observe the tech. departements in the companies, that have build up castles, growing up a very large and high walls all around the tech. deps., using hermetic symbols, citing unfindable specs, denied support to the collegues. It seems, the higher and thiker the walls of the castle, the higher the importance of tech departements.
But with battles, with castles, with fights there shall be only loosers. The winning of one departement (note, a generic deps) is ... the loosing of the company.

Have you heard of supplier-customer chains in the company?
Nobody warned, informed, in charged all you that there are suppliers of the internal customers.
The situation you are living should be very, very dangerous, because these and similar behaviours shall carry out out of game you, your departements, and the companies out of the market.

Let me say more:
As tech. people in the company, you and your activities are operating in (inside) one or more processes with one or more purposes and targets. All these processes interact each others toward a main purpose or objective: the company's objective (you know, I immagine)
You should see yourselves inside these processes to promote them.
You should see as a supplier of internal customers with various needs about data, completeness, readibility, usability.

As tech. people in the company, your duties should be focussed toward two directions:
1. supplying correct data, clear drawings, simple specifications and instructions, spreading the know-how to the &quot;company&quot; in order to obtain the ....&quot;final objective&quot;.
2. increasing the quality of informations through updating the know-how, acquiring new one, training, coaching in order to reduce misunderstandings, reading faults, wasting of time and, at the same time improve the flowing of the infos inside (and outside) of the company.

At the end I can advise you: discover this reality, it is going in an opposite direction you adopted: no fights but cooperation.
Use the KISS (Keep It Smart&Simple) approach to avoiding complexity, redondancy, misunderstandings.
Do not build thick walls around you, but, viceversa, destroy the existing walls going toward the needs of your internal customers.
Improve the &quot;knowledge&quot; of the process where you and your customer are operating.


Remember: .. flowing in the process ... in the same direction of the others.

Gianfranco

 

[ivymike]

Are you saying that you should &quot;cooperate&quot; with the process, no matter how poorly it is set up, rather than point out inefficiencies? I'd always heard that it was the responsibility of every employee to try to point out inefficiencies within the company so that they could be eliminated, even if this meant challenging the core beliefs of the organization? How does this fit in with &quot;flowing in the process?&quot;

Suppose that the requested changes to the drawings will save 15 man-hours per year during inspection, but they'll require an additional 300 man-hours per year in engineering when the drawings are revised. Isn't it the obligation of the engineers to point out that the process would work better if the inspection information were put on a separate drawing (or sheet), so that it could be revised independently?

 

[Gianfranco]

Dear ivimike,

Cooperation means:
a) working together toward the same objective;
b) reducing inefficiencies along the process and, moreover, reducing the lenght of the process itself and, above all, updating systematically and dynamically the process at the changes, mutations of the suppliers, market, technologic, social environments.
c) transforming one constraint, or one problem, in improvements of performances of the company along the time.
Toward where? In order to assuring the competitiveness and the company/process &quot;health&quot; along the time.

Traditionally all the operations and activities of the process could be interested in these improvements. The modern &quot;Theory of Constraint&quot; (known as TOC, a managment approach introduced in US by Goldratt 15 years ago) says that is more important to reducing the ineffiencies mainly on the bottle necks. Acting on the bottle neck the flowing rate of the process increases faster than the acting on all the process' inefficiencies.

BTW: I warn you that all the automotive customers (and suppliers), now, request those flagnotes!!

In the hypotesis of a mandatory flagnoting, under a work/time study point of view, we can do the following consideration.

If the tech department is a bottle neck it shall be useful transferring the flagnotes at the Quality Dep.; otherwise, if the Quality Departement is a bottle neck it is necessary drawing down the flagnotes on Tech. Dep.

In which condition are you operating?

Let me do an observation on the hour - man extimates.
Are you sure of the activities times?
Actually the quality departement points out the characteristics to be controlled or measured or checked indentifing them on drawing. How? On all dimensions? On all attributes? Is the quality of the product set by the tech dep or by QA dep or by a team? Let's go ahead.
QA departement place down 1, 2, 3, 4, 5 etc. on the drawing. I, and you, can imagine it: by hand, by a ink-print device, others.
You say the inspection departement spend 15 hours man per years and, for the similar task the tech departement spends 300 hmpy. ??????
I can say to you that the Quality Dep surely spends much more than 15 hmpy. It spends much more of 300 man hours/year for this!

And now let's talk about the possible solutions.
I do not know what is the CAD evironment you are using. But, if you are using a medium or high performance CAD Systems, I am sure, it is possible to develop a small routine (in Fortran, C++, Prolog languages) to flagging and numbering the pre-selected characteristics (by tech dep. or team) to be checked for QC/process, customers, mandatory purposes.

Do you agree with these observations?
Is the solution feasible on your Cad System?

Gianfranco

 

[ivymike]

Simply making the changes on a drawing is not the extent of the work involved in making a revision to a drawing. At my previous employer, each change required weeks worth of paperwork pushing to go through the system. It wouldn't have made much of a difference if I was making the drawings with crayons on my lunch bag - the time to put a revision through was 5% (or less) CAD time, and 95% working through the system. Aside from prototypes, parts were not typically inspected (at all) unless a problem arose somewhere in production. Engineering drawings, in contrast, were subjected to intense scrutiny.

 

[Hush]

Gianfranco,

I am in complete agreement that building thick castle walls around your department is counter-productive. On the other hand “flowing in the process ... in the same direction of the others” sounds like the mantra of a lemming as it jumps off the cliff into the sea. Resistance to incompletely formed ideas is as important as cooperation. A good debate will generate more advances and disseminate ideas faster than will blind acquiescence.

No customer, internal or external, will be well served by the attitude; if that’s what you want that’s what you get. Rather you need to determine what the customer’s true requirements are (which are not necessarily what he or she states they are) then determine how you can meet them and more importantly, whether you can deliver on time and in budget given your available resources. If you find you can’t deliver then the customer has to be told sorry we can’t do it.

 

[MadMango]

I think we are getting off the focus of this thread.

The original request from McLeod's quality department was to assign ascending numbers to each dimension so they could use these numbers during their inspection of the parts, so they coincided with their inspection forms. The only way McLeod could do this was by placing flagnotes next to every dimension on the part drawing, per his quality department's request.

He was asking if anyone has seen this request put to practice, and if ASME Y14.5M could support his desire to resist putting these flagnotes on every dimension.

Gianfranco, you are 100% correct that within every company there are Customers and Suppliers. Engineering must supply Manufacturing/Purchasing good documentation in order to ensure their design intent is carried over to the physical part. Quality must fill the position (Customer Service) of ensuring that Manufacturing has supplied Production accurate parts that reflect the design intent of Engineering.

Engineering can identify all dimensions of a part through the proper use of GD&T (Geometric Dimensioning and Tolerancing) as outlined in ASME Y14.5M without the need of added flagnotes.

***

It is my opinion that McLeod's Engineering department should revisit GD&T use, perhaps apply more of it, and their Quality Department should be trained in how to understand its use. If properly applied, there is no need for the requested additional flagnotes on each dimension. If their Quality Department insists on this, then I believe that McLeod should suggest that his Quality Department create and maintain their own Quality Inspection Drawings that have these added inspection flagnotes.

&quot;Happy the Hare at morning for she is ignorant to the Hunter's waking thoughts.&quot;

 

[swertel]

I would have to agree with MadMango. Seems to me McLeod's Quality Department is a little lacking on documentation skills.

To add to Mango's opinion, I pose this question. Why is Quality concerned with each dimension on the drawing? Not every dimension is a critical dimension to fit, form, and function, is it? There are standard way's of identifying critical features that either need to be validated, calibrated, or inspected. If the engineers mark the inspection dimensions, then there shouldn't be many duplicate values. Then rather than saying dimension #1 is out of spec, they can actually say dimension 1.125+/-.002 is actually 1.121.

--Scott

 

[Curmudgeon]

Just a couple cents from the sideline:

Several of the posters above seem to be getting into the 'my way or the highway' mindset. I mean, they seem to feel there is only two options available.
A. Print out the Engineering Prints with all the Flags requested by the Inspectors, cluttering the prints for any other users.
or
B. Fighting this request tooth and Nail, and making the Inspectors figure out the process for themselves.

Might I suggest that there is at least one other - -much less stressful solution?
C. Create *seperate* Inspection Prints for the Inspection department. You might easily do this by two methods (depending upon your internal needs).
First, you could create 'new' Inspection Prints from the Engineering Prints, by merely copying the latter, adding the flags and notes needed, and saving to a seperate file.
Second, you might merely add the flags for Inspection Prints to the Engineering Prints, but on a seperate 'Inspection Layer', that might be readily turned off/frozen until needed.

The 'regular' Engineering prints will not be cluttered with the extraneous information, and your inspection crew will be pleased with your giving them their own 'special' documents.

But those are just my two cents....

Curmudgeon

 

[Curmudgeon]

and a couple more pennies....

If, on the other hand, your upper management is too short-sighted to understand that cluttered prints scattered hither and yon is a 'Bad Thing' - - then co-operate with them. Fully. Horribly.

Make sure the prints are hideously un-readable with the (ever-so-slightly) over-sized flags all over the print. In addition, give them flags that are similar to the 'regular' note flags - - just to add to the confusion. It will take a couple of weeks or months, but the screaming, wailing and gnashing of teeth will eventually reach the ears of the upper-management.

And that little memo you sent earlier (that this was a 'Bad Idea') will save your behind, then.

Curmudgeon

 

[Hush]

Perhaps if we knew what the end purpose of the flagnotes was, someone could offer you a better alternative. Are they for quality control, statistical process control, programming, or a six sigma project gone awry? I think a lot of us, myself included, are making invalid assumptions as to what your quality department is trying to acheive.

 

[McLeod]

To answer several of the queries and comments in this thread:

The manufacturing and inspection staff in one of the factories want the flagnotes because they believe that it makes dimensions and note requirements easier to find for the machinists making the parts and the quality techs performing first-article inspection (which includes all dimensions and is done for each production lot). Their inspection report forms are not generic - each is already set up with all of the dimensions on the print listed out by flag number and the actual dimension and tolerance. Currently, the QE's for that area take the released engineering drawing CAD file and add the flagnotes themselves. That reference drawing does not get released through the engineering change order system, but rather is controlled locally by the factory QE's. It is that reference drawing which is sent to the floor for the techs to use in the manufacturing and inspection processes. They have been pushing for flagnotes to be added to the original engineering drawings because (a) then they would not have to number everything themselves, and (b) our QA managers want to get rid of the reference prints, which are &quot;uncontrolled&quot; or simply &quot;locally controlled&quot;, depending on whom you ask.

Several problems with the flagnotes have already been noted - the clutter, the increase in drafting time, the increase in change requests, etc. My overall assessment has been that the unquantified benefit to one manufacturing area would result in a disproportionate cost to the rest of the organization. This is unacceptable, especially considering that the mfg. area has other workable alternatives that do not negatively impact everyone else:

1. If they are dead set on keeping their inspection forms as they are, they can release the &quot;reference&quot; prints through the engineering change system and make them official. At least then the benefit and the cost are localized.

2. They could use the standard methods on their forms for locating requirements on prints - dimensions by sheet # and zone #, notes by sheet # and note #. (If the machinists and inspectors are still having trouble finding the dimensions, then perhaps the print is just poorly drafted, and should be re-arranged for readability.)

Using layers as a compromise is not a workable option at this time, since (a) the drawings files are converted to PDF format when they are made available on the intranet, and (b) the flagnotes would still have to be controlled with the rest of the drawing, so the engineering change difficulties would remain.

We do currently mark critical dimensions by enclosing them in the flat oval balloons, and we do also apply GD&T to our designs, but neither of these has any relevance to mfg's proposal or its motivation.

The good news is that reason has, for the moment, prevailed. Everyone's contributions to the thread have helped me to get some outside perspective and formulate my recommendations and debating points.

Thanks,
McLeod